Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 720 insertions, 0 deletions

diff --git a/gfx/harfbuzz/src/hb-font.hh b/gfx/harfbuzz/src/hb-font.hh
new file mode 100644
index 0000000000..f503575c34
--- /dev/null
+++ b/gfx/harfbuzz/src/hb-font.hh
@@ -0,0 +1,720 @@
+/*
+ * Copyright © 2009  Red Hat, Inc.
+ * Copyright © 2011  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Red Hat Author(s): Behdad Esfahbod
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_FONT_HH
+#define HB_FONT_HH
+
+#include "hb.hh"
+
+#include "hb-face.hh"
+#include "hb-shaper.hh"
+
+
+/*
+ * hb_font_funcs_t
+ */
+
+#define HB_FONT_FUNCS_IMPLEMENT_CALLBACKS \
+  HB_FONT_FUNC_IMPLEMENT (get_,font_h_extents) \
+  HB_FONT_FUNC_IMPLEMENT (get_,font_v_extents) \
+  HB_FONT_FUNC_IMPLEMENT (get_,nominal_glyph) \
+  HB_FONT_FUNC_IMPLEMENT (get_,nominal_glyphs) \
+  HB_FONT_FUNC_IMPLEMENT (get_,variation_glyph) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_h_advance) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_v_advance) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_h_advances) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_v_advances) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_h_origin) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_v_origin) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_h_kerning) \
+  HB_IF_NOT_DEPRECATED (HB_FONT_FUNC_IMPLEMENT (get_,glyph_v_kerning)) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_extents) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_contour_point) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_name) \
+  HB_FONT_FUNC_IMPLEMENT (get_,glyph_from_name) \
+  HB_FONT_FUNC_IMPLEMENT (,draw_glyph) \
+  HB_FONT_FUNC_IMPLEMENT (,paint_glyph) \
+  /* ^--- Add new callbacks here */
+
+struct hb_font_funcs_t
+{
+  hb_object_header_t header;
+
+  struct {
+#define HB_FONT_FUNC_IMPLEMENT(get_,name) void *name;
+    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+  } *user_data;
+
+  struct {
+#define HB_FONT_FUNC_IMPLEMENT(get_,name) hb_destroy_func_t name;
+    HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+  } *destroy;
+
+  /* Don't access these directly.  Call font->get_*() instead. */
+  union get_t {
+    struct get_funcs_t {
+#define HB_FONT_FUNC_IMPLEMENT(get_,name) hb_font_##get_##name##_func_t name;
+      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+    } f;
+    void (*array[0
+#define HB_FONT_FUNC_IMPLEMENT(get_,name) +1
+      HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+		]) ();
+  } get;
+};
+DECLARE_NULL_INSTANCE (hb_font_funcs_t);
+
+
+/*
+ * hb_font_t
+ */
+
+#define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INSTANTIATE_SHAPERS(shaper, font);
+#include "hb-shaper-list.hh"
+#undef HB_SHAPER_IMPLEMENT
+
+struct hb_font_t
+{
+  hb_object_header_t header;
+  unsigned int serial;
+  unsigned int serial_coords;
+
+  hb_font_t *parent;
+  hb_face_t *face;
+
+  int32_t x_scale;
+  int32_t y_scale;
+
+  float x_embolden;
+  float y_embolden;
+  bool embolden_in_place;
+  int32_t x_strength; /* x_embolden, in scaled units. */
+  int32_t y_strength; /* y_embolden, in scaled units. */
+
+  float slant;
+  float slant_xy;
+
+  float x_multf;
+  float y_multf;
+  int64_t x_mult;
+  int64_t y_mult;
+
+  unsigned int x_ppem;
+  unsigned int y_ppem;
+
+  float ptem;
+
+  /* Font variation coordinates. */
+  unsigned int instance_index;
+  unsigned int num_coords;
+  int *coords;
+  float *design_coords;
+
+  hb_font_funcs_t   *klass;
+  void              *user_data;
+  hb_destroy_func_t  destroy;
+
+  hb_shaper_object_dataset_t<hb_font_t> data; /* Various shaper data. */
+
+
+  /* Convert from font-space to user-space */
+  int64_t dir_mult (hb_direction_t direction)
+  { return HB_DIRECTION_IS_VERTICAL(direction) ? y_mult : x_mult; }
+  hb_position_t em_scale_x (int16_t v) { return em_mult (v, x_mult); }
+  hb_position_t em_scale_y (int16_t v) { return em_mult (v, y_mult); }
+  hb_position_t em_scalef_x (float v) { return em_multf (v, x_multf); }
+  hb_position_t em_scalef_y (float v) { return em_multf (v, y_multf); }
+  float em_fscale_x (int16_t v) { return em_fmult (v, x_multf); }
+  float em_fscale_y (int16_t v) { return em_fmult (v, y_multf); }
+  float em_fscalef_x (float v) { return em_fmultf (v, x_multf); }
+  float em_fscalef_y (float v) { return em_fmultf (v, y_multf); }
+  hb_position_t em_scale_dir (int16_t v, hb_direction_t direction)
+  { return em_mult (v, dir_mult (direction)); }
+
+  /* Convert from parent-font user-space to our user-space */
+  hb_position_t parent_scale_x_distance (hb_position_t v)
+  {
+    if (unlikely (parent && parent->x_scale != x_scale))
+      return (hb_position_t) (v * (int64_t) this->x_scale / this->parent->x_scale);
+    return v;
+  }
+  hb_position_t parent_scale_y_distance (hb_position_t v)
+  {
+    if (unlikely (parent && parent->y_scale != y_scale))
+      return (hb_position_t) (v * (int64_t) this->y_scale / this->parent->y_scale);
+    return v;
+  }
+  hb_position_t parent_scale_x_position (hb_position_t v)
+  { return parent_scale_x_distance (v); }
+  hb_position_t parent_scale_y_position (hb_position_t v)
+  { return parent_scale_y_distance (v); }
+
+  void parent_scale_distance (hb_position_t *x, hb_position_t *y)
+  {
+    *x = parent_scale_x_distance (*x);
+    *y = parent_scale_y_distance (*y);
+  }
+  void parent_scale_position (hb_position_t *x, hb_position_t *y)
+  {
+    *x = parent_scale_x_position (*x);
+    *y = parent_scale_y_position (*y);
+  }
+
+  void scale_glyph_extents (hb_glyph_extents_t *extents)
+  {
+    float x1 = em_fscale_x (extents->x_bearing);
+    float y1 = em_fscale_y (extents->y_bearing);
+    float x2 = em_fscale_x (extents->x_bearing + extents->width);
+    float y2 = em_fscale_y (extents->y_bearing + extents->height);
+
+    /* Apply slant. */
+    if (slant_xy)
+    {
+      x1 += hb_min (y1 * slant_xy, y2 * slant_xy);
+      x2 += hb_max (y1 * slant_xy, y2 * slant_xy);
+    }
+
+    extents->x_bearing = floorf (x1);
+    extents->y_bearing = floorf (y1);
+    extents->width = ceilf (x2) - extents->x_bearing;
+    extents->height = ceilf (y2) - extents->y_bearing;
+
+    if (x_strength || y_strength)
+    {
+      /* Y */
+      int y_shift = y_strength;
+      if (y_scale < 0) y_shift = -y_shift;
+      extents->y_bearing += y_shift;
+      extents->height -= y_shift;
+
+      /* X */
+      int x_shift = x_strength;
+      if (x_scale < 0) x_shift = -x_shift;
+      if (embolden_in_place)
+	extents->x_bearing -= x_shift / 2;
+      extents->width += x_shift;
+    }
+  }
+
+
+  /* Public getters */
+
+  HB_INTERNAL bool has_func (unsigned int i);
+  HB_INTERNAL bool has_func_set (unsigned int i);
+
+  /* has_* ... */
+#define HB_FONT_FUNC_IMPLEMENT(get_,name) \
+  bool \
+  has_##name##_func () \
+  { \
+    hb_font_funcs_t *funcs = this->klass; \
+    unsigned int i = offsetof (hb_font_funcs_t::get_t::get_funcs_t, name) / sizeof (funcs->get.array[0]); \
+    return has_func (i); \
+  } \
+  bool \
+  has_##name##_func_set () \
+  { \
+    hb_font_funcs_t *funcs = this->klass; \
+    unsigned int i = offsetof (hb_font_funcs_t::get_t::get_funcs_t, name) / sizeof (funcs->get.array[0]); \
+    return has_func_set (i); \
+  }
+  HB_FONT_FUNCS_IMPLEMENT_CALLBACKS
+#undef HB_FONT_FUNC_IMPLEMENT
+
+  hb_bool_t get_font_h_extents (hb_font_extents_t *extents)
+  {
+    hb_memset (extents, 0, sizeof (*extents));
+    return klass->get.f.font_h_extents (this, user_data,
+					extents,
+					!klass->user_data ? nullptr : klass->user_data->font_h_extents);
+  }
+  hb_bool_t get_font_v_extents (hb_font_extents_t *extents)
+  {
+    hb_memset (extents, 0, sizeof (*extents));
+    return klass->get.f.font_v_extents (this, user_data,
+					extents,
+					!klass->user_data ? nullptr : klass->user_data->font_v_extents);
+  }
+
+  bool has_glyph (hb_codepoint_t unicode)
+  {
+    hb_codepoint_t glyph;
+    return get_nominal_glyph (unicode, &glyph);
+  }
+
+  hb_bool_t get_nominal_glyph (hb_codepoint_t unicode,
+			       hb_codepoint_t *glyph,
+			       hb_codepoint_t not_found = 0)
+  {
+    *glyph = not_found;
+    return klass->get.f.nominal_glyph (this, user_data,
+				       unicode, glyph,
+				       !klass->user_data ? nullptr : klass->user_data->nominal_glyph);
+  }
+  unsigned int get_nominal_glyphs (unsigned int count,
+				   const hb_codepoint_t *first_unicode,
+				   unsigned int unicode_stride,
+				   hb_codepoint_t *first_glyph,
+				   unsigned int glyph_stride)
+  {
+    return klass->get.f.nominal_glyphs (this, user_data,
+					count,
+					first_unicode, unicode_stride,
+					first_glyph, glyph_stride,
+					!klass->user_data ? nullptr : klass->user_data->nominal_glyphs);
+  }
+
+  hb_bool_t get_variation_glyph (hb_codepoint_t unicode, hb_codepoint_t variation_selector,
+				 hb_codepoint_t *glyph,
+				 hb_codepoint_t not_found = 0)
+  {
+    *glyph = not_found;
+    return klass->get.f.variation_glyph (this, user_data,
+					 unicode, variation_selector, glyph,
+					 !klass->user_data ? nullptr : klass->user_data->variation_glyph);
+  }
+
+  hb_position_t get_glyph_h_advance (hb_codepoint_t glyph)
+  {
+    return klass->get.f.glyph_h_advance (this, user_data,
+					 glyph,
+					 !klass->user_data ? nullptr : klass->user_data->glyph_h_advance);
+  }
+
+  hb_position_t get_glyph_v_advance (hb_codepoint_t glyph)
+  {
+    return klass->get.f.glyph_v_advance (this, user_data,
+					 glyph,
+					 !klass->user_data ? nullptr : klass->user_data->glyph_v_advance);
+  }
+
+  void get_glyph_h_advances (unsigned int count,
+			     const hb_codepoint_t *first_glyph,
+			     unsigned int glyph_stride,
+			     hb_position_t *first_advance,
+			     unsigned int advance_stride)
+  {
+    return klass->get.f.glyph_h_advances (this, user_data,
+					  count,
+					  first_glyph, glyph_stride,
+					  first_advance, advance_stride,
+					  !klass->user_data ? nullptr : klass->user_data->glyph_h_advances);
+  }
+
+  void get_glyph_v_advances (unsigned int count,
+			     const hb_codepoint_t *first_glyph,
+			     unsigned int glyph_stride,
+			     hb_position_t *first_advance,
+			     unsigned int advance_stride)
+  {
+    return klass->get.f.glyph_v_advances (this, user_data,
+					  count,
+					  first_glyph, glyph_stride,
+					  first_advance, advance_stride,
+					  !klass->user_data ? nullptr : klass->user_data->glyph_v_advances);
+  }
+
+  hb_bool_t get_glyph_h_origin (hb_codepoint_t glyph,
+				hb_position_t *x, hb_position_t *y)
+  {
+    *x = *y = 0;
+    return klass->get.f.glyph_h_origin (this, user_data,
+					glyph, x, y,
+					!klass->user_data ? nullptr : klass->user_data->glyph_h_origin);
+  }
+
+  hb_bool_t get_glyph_v_origin (hb_codepoint_t glyph,
+				hb_position_t *x, hb_position_t *y)
+  {
+    *x = *y = 0;
+    return klass->get.f.glyph_v_origin (this, user_data,
+					glyph, x, y,
+					!klass->user_data ? nullptr : klass->user_data->glyph_v_origin);
+  }
+
+  hb_position_t get_glyph_h_kerning (hb_codepoint_t left_glyph,
+				     hb_codepoint_t right_glyph)
+  {
+#ifdef HB_DISABLE_DEPRECATED
+    return 0;
+#else
+    return klass->get.f.glyph_h_kerning (this, user_data,
+					 left_glyph, right_glyph,
+					 !klass->user_data ? nullptr : klass->user_data->glyph_h_kerning);
+#endif
+  }
+
+  hb_position_t get_glyph_v_kerning (hb_codepoint_t top_glyph,
+				     hb_codepoint_t bottom_glyph)
+  {
+#ifdef HB_DISABLE_DEPRECATED
+    return 0;
+#else
+    return klass->get.f.glyph_v_kerning (this, user_data,
+					 top_glyph, bottom_glyph,
+					 !klass->user_data ? nullptr : klass->user_data->glyph_v_kerning);
+#endif
+  }
+
+  hb_bool_t get_glyph_extents (hb_codepoint_t glyph,
+			       hb_glyph_extents_t *extents)
+  {
+    hb_memset (extents, 0, sizeof (*extents));
+    return klass->get.f.glyph_extents (this, user_data,
+				       glyph,
+				       extents,
+				       !klass->user_data ? nullptr : klass->user_data->glyph_extents);
+  }
+
+  hb_bool_t get_glyph_contour_point (hb_codepoint_t glyph, unsigned int point_index,
+				     hb_position_t *x, hb_position_t *y)
+  {
+    *x = *y = 0;
+    return klass->get.f.glyph_contour_point (this, user_data,
+					     glyph, point_index,
+					     x, y,
+					     !klass->user_data ? nullptr : klass->user_data->glyph_contour_point);
+  }
+
+  hb_bool_t get_glyph_name (hb_codepoint_t glyph,
+			    char *name, unsigned int size)
+  {
+    if (size) *name = '\0';
+    return klass->get.f.glyph_name (this, user_data,
+				    glyph,
+				    name, size,
+				    !klass->user_data ? nullptr : klass->user_data->glyph_name);
+  }
+
+  hb_bool_t get_glyph_from_name (const char *name, int len, /* -1 means nul-terminated */
+				 hb_codepoint_t *glyph)
+  {
+    *glyph = 0;
+    if (len == -1) len = strlen (name);
+    return klass->get.f.glyph_from_name (this, user_data,
+					 name, len,
+					 glyph,
+					 !klass->user_data ? nullptr : klass->user_data->glyph_from_name);
+  }
+
+  void draw_glyph (hb_codepoint_t glyph,
+		   hb_draw_funcs_t *draw_funcs, void *draw_data)
+  {
+    klass->get.f.draw_glyph (this, user_data,
+			     glyph,
+			     draw_funcs, draw_data,
+			     !klass->user_data ? nullptr : klass->user_data->draw_glyph);
+  }
+
+  void paint_glyph (hb_codepoint_t glyph,
+                    hb_paint_funcs_t *paint_funcs, void *paint_data,
+                    unsigned int palette,
+                    hb_color_t foreground)
+  {
+    klass->get.f.paint_glyph (this, user_data,
+                              glyph,
+                              paint_funcs, paint_data,
+                              palette, foreground,
+                              !klass->user_data ? nullptr : klass->user_data->paint_glyph);
+  }
+
+  /* A bit higher-level, and with fallback */
+
+  void get_h_extents_with_fallback (hb_font_extents_t *extents)
+  {
+    if (!get_font_h_extents (extents))
+    {
+      extents->ascender = y_scale * .8;
+      extents->descender = extents->ascender - y_scale;
+      extents->line_gap = 0;
+    }
+  }
+  void get_v_extents_with_fallback (hb_font_extents_t *extents)
+  {
+    if (!get_font_v_extents (extents))
+    {
+      extents->ascender = x_scale / 2;
+      extents->descender = extents->ascender - x_scale;
+      extents->line_gap = 0;
+    }
+  }
+
+  void get_extents_for_direction (hb_direction_t direction,
+				  hb_font_extents_t *extents)
+  {
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
+      get_h_extents_with_fallback (extents);
+    else
+      get_v_extents_with_fallback (extents);
+  }
+
+  void get_glyph_advance_for_direction (hb_codepoint_t glyph,
+					hb_direction_t direction,
+					hb_position_t *x, hb_position_t *y)
+  {
+    *x = *y = 0;
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
+      *x = get_glyph_h_advance (glyph);
+    else
+      *y = get_glyph_v_advance (glyph);
+  }
+  void get_glyph_advances_for_direction (hb_direction_t direction,
+					 unsigned int count,
+					 const hb_codepoint_t *first_glyph,
+					 unsigned glyph_stride,
+					 hb_position_t *first_advance,
+					 unsigned advance_stride)
+  {
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
+      get_glyph_h_advances (count, first_glyph, glyph_stride, first_advance, advance_stride);
+    else
+      get_glyph_v_advances (count, first_glyph, glyph_stride, first_advance, advance_stride);
+  }
+
+  void guess_v_origin_minus_h_origin (hb_codepoint_t glyph,
+				      hb_position_t *x, hb_position_t *y)
+  {
+    *x = get_glyph_h_advance (glyph) / 2;
+
+    hb_font_extents_t extents;
+    get_h_extents_with_fallback (&extents);
+    *y = extents.ascender;
+  }
+
+  void get_glyph_h_origin_with_fallback (hb_codepoint_t glyph,
+					 hb_position_t *x, hb_position_t *y)
+  {
+    if (!get_glyph_h_origin (glyph, x, y) &&
+	 get_glyph_v_origin (glyph, x, y))
+    {
+      hb_position_t dx, dy;
+      guess_v_origin_minus_h_origin (glyph, &dx, &dy);
+      *x -= dx; *y -= dy;
+    }
+  }
+  void get_glyph_v_origin_with_fallback (hb_codepoint_t glyph,
+					 hb_position_t *x, hb_position_t *y)
+  {
+    if (!get_glyph_v_origin (glyph, x, y) &&
+	 get_glyph_h_origin (glyph, x, y))
+    {
+      hb_position_t dx, dy;
+      guess_v_origin_minus_h_origin (glyph, &dx, &dy);
+      *x += dx; *y += dy;
+    }
+  }
+
+  void get_glyph_origin_for_direction (hb_codepoint_t glyph,
+				       hb_direction_t direction,
+				       hb_position_t *x, hb_position_t *y)
+  {
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction)))
+      get_glyph_h_origin_with_fallback (glyph, x, y);
+    else
+      get_glyph_v_origin_with_fallback (glyph, x, y);
+  }
+
+  void add_glyph_h_origin (hb_codepoint_t glyph,
+			   hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_h_origin_with_fallback (glyph, &origin_x, &origin_y);
+
+    *x += origin_x;
+    *y += origin_y;
+  }
+  void add_glyph_v_origin (hb_codepoint_t glyph,
+			   hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_v_origin_with_fallback (glyph, &origin_x, &origin_y);
+
+    *x += origin_x;
+    *y += origin_y;
+  }
+  void add_glyph_origin_for_direction (hb_codepoint_t glyph,
+				       hb_direction_t direction,
+				       hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
+
+    *x += origin_x;
+    *y += origin_y;
+  }
+
+  void subtract_glyph_h_origin (hb_codepoint_t glyph,
+				hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_h_origin_with_fallback (glyph, &origin_x, &origin_y);
+
+    *x -= origin_x;
+    *y -= origin_y;
+  }
+  void subtract_glyph_v_origin (hb_codepoint_t glyph,
+				hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_v_origin_with_fallback (glyph, &origin_x, &origin_y);
+
+    *x -= origin_x;
+    *y -= origin_y;
+  }
+  void subtract_glyph_origin_for_direction (hb_codepoint_t glyph,
+					    hb_direction_t direction,
+					    hb_position_t *x, hb_position_t *y)
+  {
+    hb_position_t origin_x, origin_y;
+
+    get_glyph_origin_for_direction (glyph, direction, &origin_x, &origin_y);
+
+    *x -= origin_x;
+    *y -= origin_y;
+  }
+
+  void get_glyph_kerning_for_direction (hb_codepoint_t first_glyph, hb_codepoint_t second_glyph,
+					hb_direction_t direction,
+					hb_position_t *x, hb_position_t *y)
+  {
+    if (likely (HB_DIRECTION_IS_HORIZONTAL (direction))) {
+      *y = 0;
+      *x = get_glyph_h_kerning (first_glyph, second_glyph);
+    } else {
+      *x = 0;
+      *y = get_glyph_v_kerning (first_glyph, second_glyph);
+    }
+  }
+
+  hb_bool_t get_glyph_extents_for_origin (hb_codepoint_t glyph,
+					  hb_direction_t direction,
+					  hb_glyph_extents_t *extents)
+  {
+    hb_bool_t ret = get_glyph_extents (glyph, extents);
+
+    if (ret)
+      subtract_glyph_origin_for_direction (glyph, direction, &extents->x_bearing, &extents->y_bearing);
+
+    return ret;
+  }
+
+  hb_bool_t get_glyph_contour_point_for_origin (hb_codepoint_t glyph, unsigned int point_index,
+						hb_direction_t direction,
+						hb_position_t *x, hb_position_t *y)
+  {
+    hb_bool_t ret = get_glyph_contour_point (glyph, point_index, x, y);
+
+    if (ret)
+      subtract_glyph_origin_for_direction (glyph, direction, x, y);
+
+    return ret;
+  }
+
+  /* Generates gidDDD if glyph has no name. */
+  void
+  glyph_to_string (hb_codepoint_t glyph,
+		   char *s, unsigned int size)
+  {
+    if (get_glyph_name (glyph, s, size)) return;
+
+    if (size && snprintf (s, size, "gid%u", glyph) < 0)
+      *s = '\0';
+  }
+
+  /* Parses gidDDD and uniUUUU strings automatically. */
+  hb_bool_t
+  glyph_from_string (const char *s, int len, /* -1 means nul-terminated */
+		     hb_codepoint_t *glyph)
+  {
+    if (get_glyph_from_name (s, len, glyph)) return true;
+
+    if (len == -1) len = strlen (s);
+
+    /* Straight glyph index. */
+    if (hb_codepoint_parse (s, len, 10, glyph))
+      return true;
+
+    if (len > 3)
+    {
+      /* gidDDD syntax for glyph indices. */
+      if (0 == strncmp (s, "gid", 3) &&
+	  hb_codepoint_parse (s + 3, len - 3, 10, glyph))
+	return true;
+
+      /* uniUUUU and other Unicode character indices. */
+      hb_codepoint_t unichar;
+      if (0 == strncmp (s, "uni", 3) &&
+	  hb_codepoint_parse (s + 3, len - 3, 16, &unichar) &&
+	  get_nominal_glyph (unichar, glyph))
+	return true;
+    }
+
+    return false;
+  }
+
+  void mults_changed ()
+  {
+    float upem = face->get_upem ();
+
+    x_multf = x_scale / upem;
+    y_multf = y_scale / upem;
+    bool x_neg = x_scale < 0;
+    x_mult = (x_neg ? -((int64_t) -x_scale << 16) : ((int64_t) x_scale << 16)) / upem;
+    bool y_neg = y_scale < 0;
+    y_mult = (y_neg ? -((int64_t) -y_scale << 16) : ((int64_t) y_scale << 16)) / upem;
+
+    x_strength = fabsf (roundf (x_scale * x_embolden));
+    y_strength = fabsf (roundf (y_scale * y_embolden));
+
+    slant_xy = y_scale ? slant * x_scale / y_scale : 0.f;
+
+    data.fini ();
+  }
+
+  hb_position_t em_mult (int16_t v, int64_t mult)
+  { return (hb_position_t) ((v * mult + 32768) >> 16); }
+  hb_position_t em_multf (float v, float mult)
+  { return (hb_position_t) roundf (em_fmultf (v, mult)); }
+  float em_fmultf (float v, float mult)
+  { return v * mult; }
+  float em_fmult (int16_t v, float mult)
+  { return (float) v * mult; }
+};
+DECLARE_NULL_INSTANCE (hb_font_t);
+
+
+#endif /* HB_FONT_HH */